176 PROBLEMS OF FERTILIZATION 



sample of plasma be divided in two parts, and one part 

 be saturated with egg secretions by adding a large 

 quantity of eggs, it is found that this portion has en- 

 tirely lost its inhibiting properties. This matter will 

 be discussed in more detail in a later section (see 

 chap. vii). 



A curious form of inhibition was discovered by 

 Godlewski (1911) and described by him under the name 

 "antagonism of sperm." The matter was subsequently 

 investigated by Herlant (1912). Godlewski found that 

 sperm of the annelid Chaetopterus would call forth mem- 

 brane formation in the eggs of the sea urchin Sphaer- 

 echinus. If, however, the sperm of Chaetopterus was 

 mixed in proportions ranging from equal parts to two 

 to eight with the sperm of S phaer echinus no egg of 

 Sphaerechinus would fertilize in the mixture after it 

 had stood a few minutes. The effect developed grad- 

 ually. The spermatozoa were perfectly motile, but in 

 some way they antagonized each other's action. He also 

 found that the sperm of Dentalium (mollusk) inhibited 

 fertilization of sea urchin eggs by sperm of their own 

 species used in the same way. The blood also of 

 Chaetopterus and Dentalium acts in the same way. The 

 eggs, however, remain capable of fertilization after some 

 time in the mixture by fresh species sperm. 



This author therefore attributed the effect to a recip- 

 rocal action of the sperm on one another and not to 

 an action of the mixture on the eggs. He compared 

 the phenomenon to the neutralizing effect which dif- 

 ferent cytolytic sera sometimes exert on one another, 

 and believed that it probably belonged in the same 

 category; he therefore regarded the result as evidence 



